The invention pertains to cut-resistant articles made of aromatic polyamide microfibers.
It is known that cut-resistant articles can be made of aromatic polyamide (polyaramid) fibers. In DE 29713824 a protective glove has been described the lining of which comprises flexible aramid fiber. In WO 9721334 penetration-resistant compositions have been disclosed in which yarns of aramid fibers are bonded to a polymeric continuum. This material is primarily aimed at body armor for protection against ballistic projectiles, but it is also described that the compositions can be used against sharp objects, such as knives, in gloves, sleeves, shoes, and the like. Gloves made from poly(para-phenylene terephthalate) yarn (p-aramid yarn) are commercially available, for instance, under the name Twaron(copyright) Safety Gloves.
Although these articles, in particular gloves, are suitable in many cases, there is still a need for improvement. Such improvement includes a better resistance against stubbing and cutting by sharp objects, such as nails, knives, and the like, but also increase of wear comfort, freedom of movement, and enhanced suppleness are long sought improvements.
It has now been found that cut-resistant articles with improved properties in comparison to known articles can be obtained by using microfibers of aromatic polyamide (polyaramid).
Aromatic polyamide microfibers as such are known, for instance from EP 241,681, wherein articles made of polyaramid microfilaments have been disclosed for use as ballistic protection structures. However, it is unknown for articles made of polyaramid microfilaments to have substantially improved properties with respect to cut resistance and wear comfort.
The present invention therefore pertains to articles made from polyaramid microfibers, and in particular to gloves, sleeves, and cut-protective garments in general. Woven fabrics, knits, or needle felts may be applied. A plurality of layers may be used to improve the performance, and if required, additional layers of a different material, for instance, metallized materials for additional heat protection, may be added.
The aromatic polyamide (polyaramid) may be any aromatic polyamide, such as obtained by the polymerization of an aromatic diamine and an aromatic di-acid chloride. More preferred are para-aromatic polyamides, and most preferred is poly(para-phenylene terephthalate) (PPD-T), which can be obtained from p-phenylenediamine and terephthaloyl chloride.
The aromatic polyamide is spun into microfibers in a manner known in the art and the spun fiber can be used as endless filament yarn, stretch breaking yarn or, more preferably, as spun yarn based on staple fiber. The spun yarns of this invention can be made by any appropriate spinning processes, among which can be mentioned spinning processes, such as cotton, worsted, and woolen ring spinning systems, and open end spinning processes. If staple fibers are used for the manufacture of cut-resistant articles, preferably staple fibers with a length between 38 and 100 mm are used.
The microfibers have a titer of at least 1.3 dtex (1.3xc3x9710xe2x88x924 g/m) or smaller, preferably equal to or less than 1.0 dtex (10xe2x88x924 g/m).
The cut-resistant articles of this invention such as gloves are manufactured, for instance, by knitting the yarn obtained from the aromatic polyamide microfibers.
The yarns according to the present invention are more cut-resistant than comparative standard yarns with titers above 1.3 dtex (1.3xc3x9710xe2x88x924 g/m). If gloves are made of these microfibers, the gloves have superior wear comfort in comparison with gloves with standard filaments. The gloves made with microfibers are much more supple and therefore give the user a high wearing comfort. These gloves therefore are also eminently suitable for performing subtle tasks.